Electrical ignition system for internal-combustion engines



J. L. MILTON ELECTRIC IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES 2Sheefs-$heet 1 Original Filed June 14, 1912 2 0&

[NI/EN Tm J. L. MILTON ELECTRIC, IGNITION SYSTEM FOR INTERNAL COMBUSTIONBNGINES .O'riginal Filed June 14, 1912 2 sheets-Sheet 2 Figure 3;

Patented Oct. 23, 1923.

JOHN LEWIS MILTON, OI CLEVELAND, OHIO, ASSIGNOR TO MOTOR IGNITION &

PATENT 0mm,

VICES COMPANY, A CORPORATION OF WEST VIRGINIA.

rnrncraroar. reunion srsrnm ron'mrnnnarrcomnusmon mamas.

Application filed June 14, 1912, Serial No, 703,708. Renewed January25', 1918. Serial No. 213,828.

To all whom it may concern:

Be it known that I, Jomr LEWIS MILTON, a citizen of the United States,residing at Cleveland in the county of Cuyahoga and State of hio, haveinvented a certain new and Improved Electric Ignition System forInternal-Combustion Engines, of which the following is a full,-clear,concise, and exact description, reference being had to the accompanyingdrawings, forming a part of these specifications:

My invention relates to electric ignition system for internal-combustionengines, particularly, developments pertaining to my United States CaseNo. 15, S. No. 615,184, filed March 18, 1911, and its object is toprovide means for producing hotter and more certainsparks than producedby the systems heretofore known and commonly used, without involving theuse of more apparatus and without incurring prohibitive expense. 7

'My invention also relates to these features incorporated in a dualignition system and arranged for successful battery ignition at veryhigh engine speeds.

An instance of my invention is illustrated in the accompanying drawings,in which,

Figure l is a vertical axial sectional view of the magneto machine whichmight be employed Figure 2 is an end elevation of the mag neto, with asection of the timer cover plate removed to show the location of thetimer mechanism;

Figure 3 is a portion of the condenser cover showing the location of thefixed Spark g p; 1 v

Figure 4 is a cross sectional view of the fixed spark gap device throughR-R of Figure 5 is a diagrammatic representation of the circuit;

Figure 6 is a diagrammatic representation of a modification of thecircuit;

Figure 7 shows details of the various fixed spark gaps.

' Like reference characters are applied to I the same parts throughoutthe various figures.

Referring first to Figure 5, it will be seen that the current issupplied by means of a battery, B, or a generator, G, which is providedwith a rotatable core, R, and the spark plugs in each cylinder, and inone.

instance I have shown a structural embodiment of the spark plug. Thecurrent generated by the generator G, is a low tension current, andinorder that a. high tension current may be supplied to the main sparkgap terminals, .3, s, I provide transformer coils, 1, 1, 2, 2 etceterafor each spark plug comprising a primary winding, P, and a secondarywinding, S, which is of such construction that it may withstandconsiderable heat, and may, therefore, be mounted directly on the sparkplug terminal, and carried by the porcelain, N. When the transformingmeans is thus so closely associated with the spark plug, theconsiderable greater part of the circuit is required to carry merely alowtension current. The transformer is preferably coreless, and theprimary winding is disposed outside the secondary winding, The primarywinding comprises 12% turns of No. 20 copper wire,

and the secondary winding comprises 800 turns of No. 30 copper wire. Theterminal,

.T, is" common to both windings, and the terminal, T forms the otherterminal of the primary winding, while the disk, M,

forms the other terminal of the secondary winding. The disk M, is not inelectrical across the fixed spark gap, in order to reach the electrodes,8, of the spark plugs. The details of same are clearly shown on anenlarged scale in Figure 7.

To provide two sparks simultaneously in each cylinder, two transformingcoils are employed. Figure 5 shows the primary of the coils arranged inparallels, and each group of two coils has one terminal which iscommonto the primary and secondary windings, connected with the respectivecontacts of the distributer. The other terminal of the secondary windingas before stated, is connected with one of the terminal surfaces of thefixed spark gap, while the other terminal surface of same is connectedto the spark gap of the spark plug, one terminal of which is grounded,as indicated; the other terminal of each primary winding is connectedwith a common conductor, g,*which leads to the condenser, F, which hasits other terminal connected to the ground circuit,

as indicated in Figure 5. The connecting wire, 7: is placed across thegenerator winding, W, when switch blade, Z is in contact with point Z orthe battery, B, and selfinduction coil B when switch blade Z is placedon contact Z Condenser, E, and fixed spark gap, X, are placed in bridgeof generator winding, W.

In Figure 6, two coils are shown for one cylinder; the coils of theother three cylinders are not shown, as the additional coils are merelyrepetitions of the ones shown. Here the primary coils P are shownconnected in series with each other, and are in turn connected to onesegment of the distributer A The other end of t-he primary coil connectsby conductor 9 to the fixedcontact 71, of the timing device, which isconnected to the condenser, E, as shown. The other end of the condenserbeing connected to the spark gap, the timing device is thus.

shunted by a branch circuit, which includes the condenser, E, and aspecial spark g p, :11. The generator winding has a condenser, F, in thebridge of its winding. The secondaries S of these coils of Figure 6 areconnected independently of each other, one end of each being directlyconnected to the primary of its own coil. The secondary current fromeach coil is conducted across the fixed spark gaps, y, to the spark pluggaps, 8, on to the ground circuit. It is obvious that an impulse of lowpressure current sent to the primaries of these coils willsimultaneously cause two sparks to the two spark plugs.

The illustrations, Figures 1, 2, 3 and l,- are full size andare drawnsubstantially to scale. The pole frame is indicated at 6, and the twohorse-shoe magnets which are associated therewith, are shown at 6'6'.()n one side the pole'frame is provided with an end plate, 7, which issecured thereto and to the adjacent magnets in any suitable manner, andprovides the bearings for one of the armature shafts. 0n the other sideof the pole frame is provided a small end plate, 8,

which is secured theretoin any suitable man matinee ner, provides thebearing for the opposite end of the armature shaft. The armature isillustrated at 9, and is mounted on trun nions, 10 and 11, which arejournaled in suitable bearings, 12 and 13, in the respective end plates7 and 8. The armature winding is illustrated at W; one terminal thereofis grounded to the machine, and the other is connected by means of wire15 to the ring, 15, carried on the trunnion, 11, but insulated therefromby means of a collar, 16, the ring 15 being engaged by-the brush, 17which makes electrical connection with the binding post, 19, through thecup, 18.

The trunnion, 10, where it extends beyond the bearing, is provided witha cam, o, with which is associated a follower, 21, mounted upon afollower arm, is, suitably pivoted to a cup shaped housing structure,24, which is slipped in a circular wall surrounding the bearing, 13. Aconducting blade, 32, affords means of carrying current from the bindingpost, 32, to the timing device, the binding post 32 being connectedthrough the arm 32*, spring contact member 32, and insulated rivet, 32and blade, 32, to the timing device, thus dispensing with the usualmoving conductor which is ordinarily connected to the conducting bladeof the timing device.

The binding post, 19, which is supported on the condenser case, E andinsulated therefrom by the collar of insulating terial 19, affords meansfor securing a contact to the generator winding, W.

The low tension distributer device, A is preferably driven separatelyfrom the engine at cam shaft speed, so as to dispense with one pair ofgears generally used on a multiple cylinder magneto, also to place thewiring away from the magneto, all making for simplicity.

The distributer is of the low tension type with a roller a, carried byan arm, a, which is carried by another arm. A. A spring, a", holds theroller in pOSitl G contact with the inner surface of the distributer.The conductor, 71 has one end in contact with the distributer arm, A,through a brush which is not shown. As the arm, A, rotates, the currentimpulses from the sources of current are progressively led to thevarious coils associated with the several cylinders.

In the timing device, the follower arm, A, forms a movable member, and,his a stationary member. which is carried by and insulated from thecup-shaped housing, 24, and is associated therewith. The stationarymember is in the form of a screw which may be set in any adjustedposit-ion, mounted in a supporting piece, 28, secured to the cup bymeans of a bolt, 29, and nut, 31, but insulated therefrom by means ofinsulation 30. The housing, 24, can be turned by means of an a m, 25, rg y a tached. th reto to adjust llO the position of-the timer to'advanceor retard v fixed spark gap X-is illustrated in Figures 3, and 4, whereit is shown assembled in the condenser case. The metallic disk, M, beingfixed to the mind or body of the case. The metallic isk M being fixed tothe cupshaped conductor holder, M, but insulated from the disk M by amica washer, M. M is a cup-shaped fiber piece which holds the severalparts rigidly in place by means of screws, M. The same generalarrangement is preferably used on all the fixed spark gaps in thissystem. The contact holder, M, is electrically connected by means ofconductor, g, to condenser, E, which is, in turn, connected to the fixedcontact member h, of

the timer mechanism through the rod, 32',

supporting lug, 32 arm, 32 spring contact member, 32 all of which areinsulated from the ground circuit shown in Figure 1) to the rivet 32which is in turn in electrical contact with stationary timer contact71.. The condensers, E and F are shown disposed within the horse-shoemagnets. A special feature is that the case carries as an assembledunit, the fixed spark gap, X, the condensers E and F the brush holder,18, the binding post 32 and means for dispensing with the usual movablewire connection. The insulation material, E tightly clamped to themagneto frame, serves the double purpose of supporting the condensersand formmg a gasket to exclude foreign substances. Condenser F is shownwith one end grounded at f, and the other in contact with thebrush-holder, 18, by means of a conductor f which is carried throughcondenser case tothe brush holder, 18.

Since spark plugs are provided for the four cylinder engine, thedistributer roller a must be geared to the engine and generator in a twoto one ratio, so that the armature may make two complete revolutionsduring a single revolution of the roller, a Assuming the distributerroller to be in electrical connection with any one of the contacts ofthe distributer, it will be seen that the current, whenever generatedupon rotation of the armature may be forced from one terminal of thewinding, W, or from the battery, B, to the distributer roller, 01.,thence through the distributer contact a, thence through the primarywindings p, to the associated transformer coils, thence through theconductor g, to the condenser as shown in Figure 5, on to the stationarycontact of the timing device, or interrupter, as shown in Figure 6, andthen through the movable member, 70, thereof, and back to the otherterminal of the winding, W, or to the battery, B. The cam mechanism istimed to open the interrupter contacts slowly when the spark is to beproduced in the engine cylinder. It has been found that a batteryarrangement for operating this system, substituted for the generator,works very satisfactory-at low engine speeds, but as the s ed increases,there is a constant diminishing of volume and consequent irregularity ofthe sparkin in the cylinders. To meet this condition, have provided avariable resistance kick coil B having an adjustable contact arm, B, asillustrated in Fig. 5 which as the speed increases and the sparking ortimer position is advanced in accordance with general practice, maybeeither automatically or manuall adjusted, changing the resistance or conuctivity of said coils so as to admit a greater volume of current. Bythis system, regular sparking from battery current is secured at veryhigh engine speeds. I may also couple the arm B to the adjusting arm 25on the cup 24 by means of which the times position is advanced orretarded, so that they may be moved together.

In the use of the device disclosed in my co-pending application No.615,184, it has been shown that when operated on the four cylinderignition system, firing in the wrong cylinder frequently occurs.Considering Figure 5,-it will be seen that by means of the commonconductor, 9 and wires 9, electrical impulses can find their way fromone transforming coil to another one, if the spark gaps, 3 are not incircuit. The circuit through one of the transformers and spark plugs inthe cylinder not to be fired, and in which the gases are consequentlynot under compression, would be of sufiiciently low resistance to allowthe stray impulses to cause ignition in one of the other cylinders.However, when the auxiliary fixed spark gaps of the type described areprovided in the secondary circuit of the trans-.

forming coils, the stray impulses are interrupted and regular correctignition follows.

To provide for causing a spark or sparks to pass in a cylinder withoutthe necessity of turning over the engine to actuate the timer mechanisman auxiliary interrupter D is provided. It will be seen that by movingblade, D, the circuit is first opened as the blade leaves one arm of thecontact member D and then closed as it comes in contact with the otherarm of the contact member D The interrupter, D, is arranged so that thecircuit will be completed for the timer mechanism to interrupt thecircuit in its regular course of operation.

A consideration of the diagrammatic circuit drawn, will show that thereare a number of approaches through which the flow of secondary currentimpulses may be forced; It is found that a high frequency currentproducing an arc of low heat value is first produced, and then as soonas the gas at s s ionized, the low tension large volume currentimmediately flows over that path, thus and a distributer, a plurality oftransformers, each having connection with a contact of said distributer,so that the primary winding thereof may be included in said primarycircuit, a plurality of secondary circuits, each having asecondarywinding in association with one of said primary windings, and

a'spark gap between said secondary winding and the spark plug electrodesin the cylinder, a shunt circuit bridging said interrupter and includinga condenser and a primary spark gap, and a condenser connected inshunt'of the armature winding.

2. In an electric ignition system for internal combustion engines, aprimary circuit,-in eluding a source of current, an interrupter and adistributer, a plurality of pairs of transformers, each havingconnection with a contact of said distributer, so that the primarywinding thereof may be included in said primary circuit, a plurality ofsecondary circuits, each having a secondary winding in association withone of said primary windings and a spark gap between each secondarywinding and the spark plug electrodes in the cylinder a shunt circuitbridging said interrupter and including a condenser, and a primary sparkgap, and a condenser connected in shunt of the armature winding.

3. In an electric ignition system for internal combustion engines, aprimary circuit, including a source of current, an interrupter and adistributer, a plurality of transformers each having connection with acontact of said distributer, so that the primary winding thereof may beincluded in said primary circuit, a plurality of secondary circuits,each having a secondary winding in association with one of said primarywindings, and a spark gap between said secondary windings and the sparkplu electrodes in the cylinders, a condenser bridging said interrupterand a condenser in shunt of the armature winding, and a fixed spark gapin series with one of the condensers.

4. In an electric ignition system for internal combustion engines, aprimary circuit including a battery and a variable selfinduction coil,means for connecting various sections of same in series with the batteryand transformers, an interrupter and a distributer, a plurality oftransformers each having connection with a contact of said distributer,so that the primary'winding thereof may be included in said primarycircuit, a plurality of secondary circuits, each having a secondarywinding in association with one of said primary windings, and a sparkgap between said secondary windings and the spark plug electrodes in thecylinders, a condenser bridging said interrupter and a condenser inshunt of the armature winding, and a fixed spark gap in series with oneof the condensers.

5. The combination with the combustion chambers of an explosion engineof sparking means therefor, comp-rising spark gaps with fixed electrodesin the several combustion chambers, condensers, discharge circuittherefor, disruptive discharge coils having their primaries periodicallydirectly included in the discharge circuit of the condensers and thesecondaries connected through fixedspark gaps to the said spark gaps inthe combustion chambers, and a charging circuit for thecondenser,including an electromotive source and a circuit controller,the discharge circuits for the condensers having low inductance and!being independent of the electromotive source, and the charging circuithaving high inductance, said circuit controller being operated by theengine to first charge thecondensers through the charging circuit, andthen to immediately discharge the condensers through said dischargecircuit thereof, including break at the circuit controller as a primaryspark gap.

6. in an ignition system for multiple cylinder engines, sparkelectrodes, transformer coils associated with each cylinder forsupplying to the electrodes a high frequency current at a high voltageso as to form an arc of low heat value, and for supplying totheelectrodes a current at relatively low voltage so as to form an arc ofhigh heat value which follows after the, arc of low heat value,comprising a source of current connected in circuit with the electrodes,a. condenser with means for charging and dis* ruptively discharging thesame, and a disruptive discharge coil, havin its primary connected tothe condenser an its secondary connected to the electrodes, and sparkgaps interposed in the secondary circuits of each transformer.

7. In an ignition system for multiple cylinder engines spark electrodes,transformer coilassociated with each cylinder for supplying to theelectrodes high frequency current of high voltage, so as to form an arcof low heat value and for supplying to the electrodes a current atrelatively low voltage, so as to form an arc of high heat-value whichfollows after the arc of low heat value, comprising a generator havingan armature winding, means for forming a local short circuit for thearmature wlndin and for opening the short circuit, two cond ensers and adisruptive discharge coil, one condenser being connected to said circuitin series with Y the primary of the coil, and the electrodes beingconnected to the armature winding in series with the secondary of thecoil, and auxilliary spark gaps interposed. in the secondary circuits ofeach transformer.

8. n an ignition system for multiple cylinder engines spark electrodes,a transformer coil containing a fixed spark gap in the secondary circuitand associated with each cylinder, a generator connected to theelectrodes, a make and break device, and connections between the latterand the winding 1 of the generator for forming a short circuit for thewinding and for interrupting the same, a condenser connected to saidcircuit and generating a high frequency current at a high voltage whensaid circuit is closed and opened, and a disruptive discharge coilhaving a primary connected to said circuit in series with the condenserand a secondary connected to the generator in series with theelectrodes, whereby a high frequency current is induced in the electriccircuit causing an arc of low heat value to be established.

9. In a multiple cylinder ignition system for internal combustionengines, a transformer ignition coil andspark plug associated with eachcylinder, means for causing a large volume of low pressure current tosuccessively pass over a spark gap in each ofsaid cylinders and a fixedspark gap interposed in each local high tension circuit.

10. In an ignition system for internal combustion engines, a source ofcurrent, a spark plug, an ignition coil having a primary connected tosaid source and a secondary connected to the plug, an external coil inseries with said primary coil and means for changing the turns of theexternal coil.

11. In an ignition system for internal combustion engines, a source ofcurrent, a spark plug, an ignition coil having a primary connected, tosaid source through an external coil and a secondary connected to theplug, means for changing the resistance and number of turns of theexternal coil.

12. In an ignition system for internal combustion engines, a source ofcurrent, a spark plug, an ignition coil having a primary connected tosaid source and a secondary connected to the lug, an external resistorin Series with sai automatic means for chan ing the resistance of theexternal resistor an controlled by the cyclic speed of the breaker.

In witness whereof, I hereunto subscribe myname this 12th day of June,A. D. 1912.

JOHN LEWIS MILTON.

Witnesses:

N. B. Wmcimsm, A. L. Snrom primary coil a breaker and

